Control system and method for supply of power to active magnetic bearings in a rotating machine

A control system and a method are disclosed arranged for redundant supply of power to active magnetic bearings (6, 7, 8) adapted for support of a shaft or rotor in a rotating machine. The control system comprises at least two control modules (12, 12') which are supplied external power (34, 34'). The control modules are connectable to a base module (13) comprising a first set of power and sensor signal pathways (A1-A4) which can be switched in to provide contact between a first control module and the active magnetic bearings, and a second set of power and sensor signal pathways (B1-B4) which can be switched in to provide contact between a second control module and the active magnetic bearings. Each control module comprises a switching mechanism (18, 18') which is controllable for connecting the control modules one at a time to the active magnetic bearings via the first set or via the second set of power and sensor signal pathways.